The decision by the Western Australian Liberals to do a preference deal with One Nation will bring some ripples for Malcolm Turnbull.

The WA Liberals have their backs against the wall – for them it’s a matter of the Barnett government desperately trying to survive against the Labor tide.

The embattled premier, Colin Barnett, said the move was “unusual, but it is a practical, pragmatic decision by the Liberal Party, because what we’re out to do is to retain government”.

And as Liberal senator Linda Reynolds told Sky: “One Nation has got a lot of support here in Western Australia”.

But inevitably, not just because of One Nation’s policies but because of the history of the Liberals’ attitude to the controversial party, the WA embrace will be challenging for Turnbull to handle. When he campaigns in the state poll, he’ll have to deal with questions about it.

The deal harms the WA Nationals who, though a different beast to their eastern cousins, and in an alliance rather than a coalition with the state Liberals, are nevertheless definitely part of the Nationals’ “family”.

Under the deal, as reported by the WA Sunday Times, the Liberals would preference One Nation above the Nationals in the upper house regional seats, in return for One Nation preferencing against Labor in the lower house. This could cost the Nationals seats and help One Nation to win the balance of power in the upper house.

Deputy Prime Minister and Nationals leader Barnaby Joyce observed cryptically on Sunday that: “Always as times grow cold … new friends are silver but old friends are gold”. It’s a fair bet it won’t be his last word on the subject. In response to earlier talk of the plan he predicted it would bring “another blue in WA”.

The WA deal will only be the start of the story. In Queensland the latest Galaxy poll has One Nation on 23% at state level, with an election likely later this year.

Federally, the Liberals are running the line that Hanson and her party are different these days.

Cabinet minister Arthur Sinodinos told the ABC on Sunday: “They are a lot more sophisticated; they have clearly resonated with a lot of people. Our job is to treat them as any other party.

"That doesn’t mean we have to agree with their policies. When it comes to preferencing, we have to make decisions – in this case a state decision, not a federal decision – based on the local circumstances.”

Compare the tone to Turnbull’s attitude before the federal election when he was asked whether he’d agree Pauline Hanson was a “known quantity in Australian politics” and “can you rule out negotiating or horse-trading with her”.

“Pauline Hanson is, as far as we are concerned, not a welcome presence on the Australian political scene. You’ve got to remember she was chucked out of the Liberal Party,” he said.

As soon as Hanson arrived in parliament with her Senate team Turnbull changed his tune. They had talks. Hanson was chuffed. When Turnbull was recently asked about the mooted WA preference deal he dodged the questioning but did note that federally: “We respect every single member and senator”.

One also has to remember that thanks to Turnbull running a double dissolution, Hanson won four Senate seats and a significant slice of the upper house balance of power.

In an ordinary Senate election she would have ended up with just her own seat. Turnbull would argue the double dissolution has made it easier to get legislation through – even though it is a tortuous process that will bring its failures – but in terms of boosting Hanson’s clout and profile the cost has been significant.

Even if she had had only one Senate seat One Nation might have surged in WA and Queensland, but her federal weight has helped – regardless of the antics of her now ex-WA senator Rod Culleton, who has been tossed out of the parliament.

One Nation, because of its power, has now been “normalised” in the Liberals’ firmament of political players, something likely to stick in the craw of their more “small-l” supporters. The Liberals are afraid of the populist party, but the days of denouncing it holus-bolus are gone.